Patti Sapone/The Star-LedgerTianle "Heidi" Li of Monroe, left, is accused of murdering her estranged husband, Xiaoye Wang, by poisoning him with thallium.

MONROE — A Monroe Township woman deliberately fed her estranged husband poison for two months until he died in January, a Middlesex County grand jury charged today.

A two-count indictment charges Tianle Li, 40, with feeding thallium, a highly toxic metal, to Xiaoye (Alex) Wang, 39, on Nov. 16, 2010 and continuing until he died on Jan. 26 at University Medical Center in Princeton.

She is charged with murder and hindering her own apprehension.

Middlesex County Assistant Prosecutor Nicholas Sewitch has said Li gave thallium to Wang at the hospital, where he had gone Jan. 14 complaining of virus-like symptoms. It was not confirmed until Jan. 25 that he suffered from thallium poisoning.

The indictment charges Li lied to police in Princeton the day Wang died. Sewitch, who has not said exactly how Li administered the poison, said when she was questioned by investigators "she denied anything to do with thallium."

Authorities charge Li, a chemist at Bristol-Myers Squibb, got the tasteless and odorless poison from work.

The couple was living in the same house with their 2-year-old son, but were in the final stages of divorce.

The prosecutor said Li applied for a rush visa for her son to take him to China, where she and her husband were born, and two days before Wang died she tried to buy airplane tickets to China.

Li was charged Jan. 28 with hindering her own apprehension and jailed. Two weeks later, she was charged with murder.

Steven Altman, Li’s attorney, said today his client denies " … having anything to do with her husband’s death." Li is in Middlesex County jail on $4.15 million bail.

James O’Neill, a spokesman for the Middlesex County Prosecutor’s Office, said no date has been set for Li’s arraignment.